Cannula assembly and medical system employing a known carbon dioxide gas concentration

Abstract

A cannula assembly and a medical system. The cannula assembly includes a cannula, a capnometer, a reservoir, a pathway, and a barrier. The cannula is positionable on the face of a patient. The capnometer measures carbon dioxide gas concentration and is operably connected to the cannula. The reservoir is adapted for containing a known concentration of carbon dioxide gas. The pathway connects carbon dioxide gas in the reservoir with the capnometer. The barrier has a first state preventing gas flow along the pathway and has a second state allowing gas flow along the pathway. The medical system includes the cannula assembly and includes a drug delivery assembly. The drug delivery assembly is adapted for administering a drug to the patient according to a drug delivery schedule based at least in part on the carbon dioxide gas concentration of the exhaled air of the patient as measured by the capnometer.

1 . A cannula assembly comprising: 
 a) a nasal and/or oral cannula disposable on the face of a patient and having a respiratory gas sampling port;    b) a capnometer which measures carbon dioxide gas concentration and which is operably connected to the respiratory gas sampling port of the cannula;    c) a reservoir adapted for containing a known concentration of carbon dioxide gas;    d) a pathway gaseously connecting carbon dioxide gas in the reservoir with the capnometer; and    e) a barrier having a first state preventing gas flow along the pathway and having a second state allowing gas flow along the pathway.    
   
   
       2 . The cannula assembly of  claim 1 , wherein the pathway includes a conduit.  
   
   
       3 . The cannula assembly of  claim 2 , wherein the conduit gaseously connects the carbon dioxide gas in the reservoir with the cannula proximate the respiratory gas sampling port of the cannula.  
   
   
       4 . The cannula assembly of  claim 3 , wherein the barrier is a valve disposed in the conduit.  
   
   
       5 . A method of using the cannula assembly of  claim 1  for verifying accurate operation of the capnometer comprising the steps of: 
 a) operating the barrier to fluidly connect the carbon dioxide gas in the reservoir with the capnometer;    b) measuring the concentration of carbon dioxide gas with the capnometer; and    c) comparing the measured and known concentrations of carbon dioxide gas to determine if the capnometer is operating accurately.    
   
   
       6 . The method of  claim 5 , wherein steps a) through c) are performed with the cannula disposed on the face of the patient during a medical procedure.  
   
   
       7 . The method of  claim 5 , wherein steps a) through c) are performed before the cannula is disposed on the face of the patient.  
   
   
       8 . A method of using the cannula assembly of  claim 1  for identifying the cannula comprising the steps of: 
 a) operating the barrier to fluidly connect the carbon dioxide gas in the reservoir with the capnometer;    b) measuring the concentration of carbon dioxide gas with the capnometer; and    c) matching the measured concentration with one of a plurality of different predetermined concentrations including the known concentration, wherein each different predetermined concentration corresponds to a different cannula.    
   
   
       9 . The method of  claim 8 , wherein each different cannula has at least one different cannula parameter than each other different cannula.  
   
   
       10 . A medical system comprising: 
 a) a cannula assembly including: 
 1) a nasal and/or oral cannula disposable on the face of a patient and having a respiratory gas sampling port;  
 2) a capnometer which measures carbon dioxide gas concentration and which is operably connected to the respiratory gas sampling port of the cannula;  
 3) a reservoir adapted for containing a known concentration of carbon dioxide gas;  
 4) a pathway gaseously connecting carbon dioxide gas in the reservoir with the capnometer; and  
 5) a barrier having a first state preventing gas flow along the pathway and having a second state allowing gas flow along the pathway; and  
   b) a drug delivery assembly adapted for administering a drug to the patient according to a drug delivery schedule, wherein the drug delivery schedule is determined by a user and/or a controller and is based at least in part on the carbon dioxide gas concentration of the exhaled air of the patient as measured by the capnometer.    
   
   
       11 . The medical system of  claim 10 , wherein the drug delivery assembly is an intravenous drug delivery assembly.  
   
   
       12 . The medical system of  claim 11 , wherein the drug is a conscious sedation drug.  
   
   
       13 . The medical system of  claim 10 , wherein the drug delivery assembly supports the reservoir, and wherein the controller is disposed in a housing containing the capnometer.  
   
   
       14 . A method of using the medical system of  claim 10  for verifying accurate operation of the capnometer comprising the steps of: 
 a) operating the barrier to fluidly connect the carbon dioxide gas in the reservoir with the capnometer;    b) measuring the concentration of carbon dioxide gas with the capnometer; and    c) comparing the measured and known concentrations of carbon dioxide gas to determine if the capnometer is operating accurately.    
   
   
       15 . The method of  claim 14 , wherein steps a) through c) are performed with the cannula disposed on the face of the patient during administration of the drug to the patient.  
   
   
       16 . The method of  claim 14 , wherein steps a) through c) are performed before the cannula is disposed on the face of the patient.  
   
   
       17 . A method of using the medical system of  claim 10  for identifying the cannula comprising the steps of: 
 a) operating the barrier to fluidly connect the carbon dioxide gas in the reservoir with the capnometer;    b) measuring the concentration of carbon dioxide gas with the capnometer; and    c) matching the measured concentration with one of a plurality of different predetermined concentrations including the known concentration, wherein each different predetermined concentration corresponds to a different cannula.    
   
   
       18 . The method of  claim 17 , wherein each different cannula has at least one different cannula parameter than each other different cannula.  
   
   
       19 . A conscious sedation system comprising: 
 a) a cannula assembly including: 
 1) a nasal and/or oral cannula disposable on the face of a patient and having a respiratory gas sampling port;  
 2) a capnometer which measures carbon dioxide gas concentration and which is operably connected to the respiratory gas sampling port of the cannula;  
 3) a reservoir containing a known concentration of carbon dioxide gas;  
 4) a pathway gaseously connecting the carbon dioxide gas in the reservoir with the capnometer; and  
 5) a barrier having a first state preventing gas flow along the pathway and having a second state allowing gas flow along the pathway; and  
   b) a drug delivery assembly which administers a conscious sedation drug to the patient according to a drug delivery schedule, wherein the drug delivery schedule is determined by a user and/or a controller and is based at least in part on the carbon dioxide gas concentration of the exhaled air of the patient as measured by the capnometer.    
   
   
       20 . The conscious sedation system of  claim 19 , wherein the drug delivery assembly is an intravenous drug delivery assembly, wherein the drug delivery assembly supports the reservoir, and wherein the controller is disposed in a housing containing the capnometer.